The specific aims of this proposal are to 1) establish a two-dimensional (2D) proteomic map of myelin proteins using high-resolution 2D gel electrophoresis, Western blotting, mass spectrometry, and bioinformatics, 2) establish a 2D proteomic map of proteins partitioned into myelin glycosphingolipid rafts and 3) investigate the role of galactocerebroside and sulfatide in myelin rafts by analyzing mutant mice lacking the enzymes cerebroside galactosyltransferase (CGT-nulI) and cerebroside sulfotransferase (CST-nulI). This project will 1) provide a comprehensive and invaluable database for the myelin biology community, 2) provide clues relating to the functional significance of galactocerebroside and sulfatide in forming rafts in myelin, 3) provide a more complete understanding of the organization of proteins and lipids in myelin as well as identify potential targets for the therapeutic intervention in many myelin related disorders/diseases